1999 EARTH SCIENCE VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| NASA RESEARCHERS DOCUMENT RAPID THINNING OF GREENLAND'S GLACIERS | G99-016 | 3/4/99 | 00:12:11 | A study of Greenland indicates a rapid thinning of glaciers along the east coast of the southern half of the island and suggests that the lower elevation portion of the ice sheet may be particularly sensitive to changes in climate. Researchers report, in the March 5. 1999 Journal of Science, the glacial thinning is too large to have resulted from increased ice surface melting or decreased snowfall. The researchers believe the thinning, as much as 30 feet (10 meters) over five-years in some locations, is the result of increasing discharge velocities of glaciers flowing into the Atlantic Ocean. |
TAPE CONTENTS: |
| ITEM (1): RAPID THINNING OF THE GREENLAND ICE SHEET - A study of Greenland indicates a rapid thinning of glaciers along the east coast of the southern half of the island and suggests that the lower elevation portion of the ice sheet may be particularly sensitive to changes in climate. The results of this study are significant because they provide the first evidence of widespread thinning of low-elevation parts of one of the great polar ice sheets. Areas of ice thinning are shown in blue, areas where ice is thickening are shown in orange.
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| ITEM (2): COLLECTING THE DATA - In 1993 and 1994, NASA researchers surveyed the Greenland ice sheet using an airborne laser altimeter. Ten flight lines flown in 1993 in southern Greenland were resurveyed in 1998. Scientists used computers to create detailed maps of changes in the ice.
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| ITEM (3): B-ROLL FROM PREVIOUS MAPPING EXPEDITIONS - In 1993 and 1994, NASA researchers surveyed the Greenland ice sheet using an airborne laser altimeter. These baseline flights were resurveyed in 1998 to determine the amount of change in the ice sheet. The 1998 results suggest that the thinning outlet glaciers must be flowing faster than necessary to remove the annual accumulation of snow.
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| ITEM (4): THE MANY FACES OF LASER ALTIMETRY- The same laser altimetry technology used to measure changes in the Greenland glaciers was also used to measure the amount of ice in the frozen northern polar cap of Mars and changes in the California coast due to severe El Nino-driven storms in 1998.
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| ITEM (5): INTERVIEW EXCERPTS - BILL KRABILL, GREENLAND MAPPING PROJECT SCIENTIST, NASA GODDARD SPACE FLIGHT CENTER'S WALLOPS FLIGHT FACILITY
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